Class: ZendeskAPI::Middleware::Request::Retry

Inherits:
Faraday::Middleware
  • Object
show all
Defined in:
lib/zendesk_api/middleware/request/retry.rb

Overview

Faraday middleware to handle HTTP Status 429 (rate limiting) / 503 (maintenance)

Constant Summary collapse

DEFAULT_RETRY_AFTER = 
10
DEFAULT_ERROR_CODES = 
[429, 503]

Instance Method Summary collapse

Constructor Details

#initialize(app, options = {}) ⇒ Retry

Returns a new instance of Retry.



13
14
15
16
17
18
19
 
# File 'lib/zendesk_api/middleware/request/retry.rb', line 13

def initialize(app, options = {})
  super(app)
  @logger = options[:logger]
  @error_codes = (options.key?(:retry_codes) && options[:retry_codes]) ? options[:retry_codes] : DEFAULT_ERROR_CODES
  @retry_on_exception = (options.key?(:retry_on_exception) && options[:retry_on_exception]) ? options[:retry_on_exception] : false
  @instrumentation = options[:instrumentation]
end

Instance Method Details

#call(env) ⇒ Object 



21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
 
# File 'lib/zendesk_api/middleware/request/retry.rb', line 21

def call(env)
  # Duplicate env for retries but keep attempt counter persistent
  original_env = env.dup
  original_env[:call_attempt] = (env[:call_attempt] || 0)

  exception_happened = false
  response = nil

  if @retry_on_exception
    begin
      response = @app.call(env)
    rescue => ex
      exception_happened = true
      exception = ex
    end
  else
    # Allow exceptions to propagate normally when not retrying
    response = @app.call(env)
  end

  if exception_happened
    original_env[:call_attempt] += 1
    seconds_left = DEFAULT_RETRY_AFTER.to_i
    @logger&.warn "An exception happened, waiting #{seconds_left} seconds... #{exception}"
    instrument_retry(original_env, "exception", seconds_left)
    sleep_with_logging(seconds_left)
    return @app.call(original_env)
  end

  # Retry once if response has a retryable error code
  if response && @error_codes.include?(response.env[:status])
    original_env[:call_attempt] += 1
    seconds_left = (response.env[:response_headers][:retry_after] || DEFAULT_RETRY_AFTER).to_i
    @logger&.warn "You may have been rate limited. Retrying in #{seconds_left} seconds..."
    instrument_retry(original_env, (response.env[:status] == 429) ? "rate_limited" : "server_error", seconds_left)
    sleep_with_logging(seconds_left)
    response = @app.call(original_env)
  end

  response
end